Diatomite: Nature’s Versatile Silica Mineral
Diatomaceous earth, commonly known as mountain flour, fossil powder or radiolaria powder, is a biogenic siliceous sedimentary rock, mainly composed of siliceous remains of diatoms and other microorganisms. There are many English translations, which appear in newspapers and periodicals: Tripoli, Tripolite, TripoliEarth, Tripoli-Powder, Diatomite.
Composition and Properties
Diatomite is a light-colored, friable sedimentary rock primarily composed of siliceous diatom skeletons. Characterized by high porosity, fine particle size, and low specific gravity, this natural material exhibits exceptional absorbency and filtration capabilities.
Applications and Forms
When processed into powder (known as diatomaceous earth or D.E.), it serves as:
• High-efficiency filter media
• Versatile absorbent
• Lightweight filler for plastics, paints, and rubber
Derived from fossilized freshwater/marine algae, diatomite finds diverse uses spanning industrial filtration to cosmetic formulations.
The main chemical component of diatomaceous earth is silicate. The content of SiO2 is one of the indicators of the content of diatoms in diatomite ore, and high SiO2 is of good quality. Diatomaceous earth contains 1%~5% water, and the water loss temperature of colloidal water is 110~250 °C
Uses of Diatomite and Diatomaceous Earth
Diatomite in Cement Production: Silica Enhancement
Diatomite serves as a critical silica-rich additive in Portland cement manufacturing, with premium grades containing >80% amorphous silica content. When introduced into the cement production process, this high-purity diatomite effectively compensates for silica deficiencies in raw materials, optimizing the final product’s SiO₂ balance essential for proper cementitious reactions. The material’s natural pozzolanic properties further enhance cement performance by reacting with calcium hydroxide during hydration.
Processing and Integration
In operational practice, mined diatomite undergoes primary crushing to achieve uniform particle sizing (typically 20-100μm) before systematic blending with conventional cement components – principally limestone and shale – at carefully calibrated ratios. This homogenized mixture then enters the kiln for clinker production, where diatomite’s microporous structure facilitates more efficient thermal transfer during calcination at 1450°C. The resulting cement exhibits improved workability and compressive strength characteristics compared to conventional formulations.
The four main uses of diatomite in the United States during 2017 were filtration (50%), light aggregate (30%), fillers (15%), and absorbents (5%). The properties of diatomite that make it useful in these applications are listed below.
- Small particle size
- High porosity
- High surface area
- Relatively inert siliceous composition
- Low specific gravity
